Or she could have been a family annihilator. These types of killers kill family members instead of strangers and often take their own lives as well. Ronald DeFeo Jr. (He killed his parents and siblings in Amityville, NY - one of the killings that was the basis for the Amityville Horror movies) and John List (killer of his mother, wife and children) were family annihilators. They are usually male but there have been cases of females killing their entire family. There are different types of family annihilators and most of the research seems to have been done on the male killers. Outwardly they seem 'normal' and have good lives but on the inside are often beset by psychological problems. I don't know anything about Dr. Edwards or her psychological makeup but maybe she felt that her world was crumbling around her no matter how perfect it seemed from the outside. Maybe the children were planning to leave the family nest and she felt that she couldn't protect them anymore (from real or imagined terrors), maybe she was beset by financial woes, maybe she suffered from an undiagnosed mental illness. If she was planning on killing herself, she might not have wanted her children to remain in this world without her protection (even though they were adults, she might have seen them as still needed her protection and guidance-due to her mental state she might not have been able to think clearly) so she killed them and then herself. This is all speculation on my part, though.